WO2006100943A1

WO2006100943A1 - Dual fuel injection system internal combustion engine

Info

Publication number: WO2006100943A1
Application number: PCT/JP2006/304775
Authority: WO
Inventors: Yukikazu Ito; Yutaka Iwami; Masato Nishigaki
Original assignee: Toyota Jidosha Kabushiki Kaisha; Yamaha Hatsudoki Kabushiki Kaisha
Priority date: 2005-03-18
Filing date: 2006-03-10
Publication date: 2006-09-28
Also published as: KR100877838B1; CN101142403B; CA2602060A1; US20060207555A1; BRPI0609367A2; CA2602060C; EP1881192A4; EP1881192B1; AU2006225810B2; EP1881192A1; RU2358143C1; US7216627B2; JPWO2006100943A1; JP4369514B2; BRPI0609367B1; KR20070101378A; CN101142403A; AU2006225810A1

Abstract

A dual fuel injection system internal combustion engine having PFI and DI fuel injection systems in which generation of knocking is prevented easily. An ECU for controlling an engine sets a fuel injection amount ratio between a DI injector and a PFI injector (step S2), and derives the maximum torque generation timing (MBT) and the knocking limit torque generation timing (TK) at the time of 100% DI, and the maximum torque generation timing (MBT) and the knocking limit torque generation timing (TK) at the time of 100% PFI, respectively, with reference to first through fourth ignition timing maps (step S3). The ECU derives a correction amount from a correction amount map (step S4), and calculates as an ignition timing a value obtained by adding the correction amount to whichever interpolation value on the delay angle side, a first interpolation value operated by interpolating MBT at the time of 100% DI and MBT at the time of 100% PFI and a second interpolation value operated by interpolating TK at the time of 100% DI and TK at the time of 100% (step S5).

Description

Specification

Dual fuel injection internal combustion engine

Technical field

TECHNICAL FIELD [0001] The present invention relates to a dual fuel injection type internal combustion engine having two of an injector of an intake pipe injection system (Port Fuel Injection system) and an injector of a direct injection system (Direct Injection System).

Background art

[0002] In an internal combustion engine of an automobile, knocking may occur when the automobile is suddenly accelerated from a low-speed running state.

[0003] Knocking is caused by incompatibility between the engine load and ignition timing, etc., and the unburned mixture in front of the propagating flame is compressed to a high temperature and self-ignited. It is a phenomenon that shakes. The occurrence of knocking may cause an abnormal rise in temperature and pressure in the combustion chamber, which may damage the combustion chamber. For this reason, various measures have been taken to prevent knocking (see, for example, Patent Document 1).

[0004] According to Patent Document 1, the ignition timing is set to the maximum torque generation timing (MB) in the low load range without the risk of knocking due to the control means for controlling the ignition timing of the internal combustion engine.

T: Minimum Spark Advance for Best Torque), and in the high load range where knocking may occur, the ignition timing is set to the knocking limit torque generation time (TK) based on the detection of knocking. The knocking limit is when the ignition timing is gradually advanced and a knocking sound (trace knock) starts to be heard.

Patent Document 1: Japanese Patent Laid-Open No. 10-141194

Disclosure of the invention

Problems to be solved by the invention

[0005] However, the invention described in Patent Document 1 is applied to the case where the ignition timing is controlled in an internal combustion engine that uses only one fuel supply device per cylinder.

[0006] On the other hand, as a fuel injection system, an intake pipe injection system (Port Fuel Injection system, hereinafter referred to as "PFI system") in which fuel is injected from an injector into an intake pipe for each cylinder, and each There is an in-cylinder injection system (Dirt Injection System, hereinafter referred to as “DI system”) in which fuel is directly injected into the cylinder for each cylinder. The PFI system has the advantage that the engine performance can be fully exerted even at low revolutions, where it is easy to form a uniform mixture of fuel and air. The DI method, on the other hand, has the advantage of being able to demonstrate high performance at high speeds because it can draw more air into the cylinder. In order to increase the combustion efficiency of the internal combustion engine using the advantages of both types, a PFI type injector and a DI type injector coexist in one cylinder, and both injectors depend on the engine speed and load conditions. It is conceivable to change the fuel injection rate.

[0007] However, the DI method and the PFI method have different timings such as the maximum torque generation timing and knocking limit torque generation timing. Therefore, there is a problem that when both types of injectors coexist, even if the invention described in Patent Document 1 is used, the optimum ignition timing cannot be achieved.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to perform simple arithmetic processing in a dual fuel injection internal combustion engine having two fuel injection systems, namely, a PFI system and a DI system. The aim is to avoid knocking and enable optimal ignition timing control.

Means for solving the problem

[0009] The invention of claim 1 is directed to an in-cylinder injector and an intake pipe injection indicator, an operating state detecting means for detecting an operating state of the internal combustion engine, and monitoring the operating state and the operating state. Depending on the fuel injection amount control means for controlling the fuel injection amount of each of the in-cylinder injector and the intake pipe injector, and the fuel injection using only the in-cylinder injector. The first ignition timing map assigned based on the operating state of the internal combustion engine so that the ignition timing of the internal combustion engine substantially coincides with the maximum torque generation timing, and the fuel injection using only the in-cylinder injector A second ignition timing map assigned based on the operating state of the internal combustion engine so that the ignition timing of the internal combustion engine substantially matches the knocking limit torque generation timing And the operating state of the internal combustion engine so that the ignition timing of the internal combustion engine in the case of fuel injection using only the intake pipe injection injector substantially coincides with the maximum torque generation timing The ignition timing of the internal combustion engine when fuel injection is performed using only the intake pipe injection injector and the third ignition timing map assigned based on! /, So that it substantially matches the knocking limit torque generation timing. Storage means having a fourth point fire timing map assigned based on the operating state of the internal combustion engine, a ratio of the fuel injection amount injected by the in-cylinder injector and the intake pipe injector, and A dual fuel injection internal combustion engine comprising ignition timing control means for controlling the ignition timing of the cylinder using the four types of timing maps.

[0010] The invention according to claim 2 calculates a basic ignition timing with reference to a value assigned in the first to fourth ignition timing maps in the operating state detected by the operating state detecting means, Depending on the ratio of the fuel injection amount, a first interpolation value obtained by interpolating the basic ignition timing of the first ignition timing map and the basic ignition timing of the third ignition timing map is calculated, and the fuel injection A second interpolation value obtained by interpolating the basic ignition timing of the second ignition timing map and the basic ignition timing of the fourth ignition timing map is calculated depending on the ratio of the amount, and the first interpolation value and 2. The dual fuel system according to claim 1, further comprising: an ignition timing calculation unit that compares the second interpolation value with the one of the retarded angle and uses the interpolated value on the retard side as the ignition timing of the cylinder. This is an injection type internal combustion engine.

[0011] The invention according to claim 3 is characterized in that the operating state detecting means includes a water temperature detecting means for detecting a water temperature of the cooling water of the internal combustion engine, and the ignition timing calculating means adjusts the water temperature of the cooling water. 3. The dual fuel injection internal combustion engine according to claim 2, wherein a correction amount of the ignition timing of the cylinder is calculated depending on the dependency.

[0012] The invention according to claim 4 is characterized in that the operating state detection means comprises an internal combustion engine speed detection means and an internal combustion engine load detection means. It is a fuel injection internal combustion engine.

[0013] The invention according to claim 5 is characterized in that the internal combustion engine load detection means includes at least one of intake air amount detection means, accelerator opening detection means, and intake pipe negative pressure detection means. 5. A dual fuel injection internal combustion engine according to claim 4, characterized in that:

The invention's effect

[0014] According to the invention of claim 1, the ignition timing is determined using the first to fourth ignition timing maps. By controlling, it becomes possible to correspond to the DI method and the PFI method with different ignition timing and knocking limit torque generation timing by simple calculation processing. In a two-line fuel injection internal combustion engine with a fuel injection system, knocking can be avoided and the optimal ignition timing can be set by a simple calculation process.

[0015] According to the invention of claim 2, in the dual fuel injection internal combustion engine having the dual fuel injection methods of the PFI method and the DI method, the injector for in-cylinder injection according to the operating state of the internal combustion engine Even when adjusting the fuel injection amount between the intake pipe injector and the intake pipe injector, the ignition timing without any complicated calculation process is always used for internal combustion by using only the four ignition timing maps. It is possible to maintain the state suitable for the operating state of the engine, avoid the occurrence of knocking, and set the optimal ignition timing.

[0016] According to the invention of claim 3, the temperature of the cooling water of the internal combustion engine is detected by the water temperature detecting means, and the correction amount of the ignition timing is calculated depending on the water temperature, thereby affecting the ignition timing. This makes it possible to adjust the ignition timing based on the warm-up state of the internal combustion engine, which is likely to affect the engine, and to improve the accuracy of ignition timing control.

[0017] According to the invention of claim 4, the operating state of the internal combustion engine can be detected by the internal combustion engine rotational speed detection means and the internal combustion engine load detection means, and the rotational speed and load of the internal combustion engine are used as parameters. It is possible to realize ignition timing control, and to realize optimum ignition timing control with high accuracy.

[0018] According to the invention of claim 5, at least one of intake air amount detection means, accelerator opening detection means, and intake pipe negative pressure detection means is provided as an internal combustion engine load detection means. Accurate detection of the amount of load applied to the engine can be realized, and ignition timing control can be performed with high accuracy.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing an engine according to an embodiment of the present invention.

FIG. 2 is a plan view of a block in which a PFI injector according to the embodiment is provided.

3 is a front view of FIG. 2 according to the same embodiment. FIG.

FIG. 4 is a control block diagram in the engine according to the embodiment. FIG. 5 is a schematic diagram of an ignition timing map in the engine according to the embodiment.

FIG. 6 is a schematic diagram of a correction amount map in the engine according to the embodiment.

FIG. 7 is a schematic diagram showing the principle of ignition timing control in the engine according to the embodiment.

FIG. 8 is a flowchart showing an ignition timing control procedure in the engine according to the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described.

1 to 8 show an embodiment of the present invention.

First, the configuration will be described. Reference numeral 11 in FIG. 1 denotes a V-type 6-cylinder engine that is an “internal combustion engine”. An intake port 13 and an exhaust port 14 are formed for each cylinder 12, and each cylinder 12 An in-cylinder injector (hereinafter referred to as “DI injector” t) 15 and an intake pipe injector (hereinafter referred to as “PFI injector”) 16 are provided for each. Fuel is directly injected into the cylinder 12 (combustion chamber) from the DI injector 15 and mixed with air in the cylinder 12, and fuel is injected from the PFI injector 16 into the intake port 13. The air is mixed with the flowing air and sucked into the cylinder 12, and the ignition plug 14a is ignited at a predetermined timing.

[0023] In addition, for each cylinder 12, an intake valve 18 that opens and closes the intake port and an exhaust valve 19 that opens and closes the exhaust port are disposed. By opening the intake valve 18, the intake port 13 is connected to the intake port 13 from the surge tank 20. Clean air is drawn into the cylinder 12 (combustion chamber) through the cylinder.

[0024] Each DI indicator 15 provided for each cylinder 12 is connected by a DI delivery pipe 23, and each PFI indicator 16 is connected by a PFI delivery pipe 24. The DI delivery pipe 23 is connected to a cylinder injection system pipe ( (Hereinafter referred to as “DI piping”) 26 is connected to the fuel tank 28 so as to circulate, and the PFI delivery pipe 24 is also connected to the fuel tank 28 via the intake pipe injection system piping (hereinafter referred to as “PFI piping”) 27. (See Figures 1 through 4).

[0025] As shown in FIG. 4, fuel is sent to the DI delivery pipe 23 at a predetermined high pressure by a fuel pump 31 and a high-pressure pump 32, and the PFI delivery pipe 24 is fed with a fuel. Fuel pump 31 will deliver fuel at a lower pressure than DI delivery pipe 23! Since the DI injector 15 directly injects fuel into the high-pressure cylinder 12, a high pressure is required.

Each of these injectors 15 and 16 has a desired amount of fuel sent by a pump 31 and 32 by a solenoid valve (not shown) opened for a predetermined time (injection time). Configured to inject fuel! RU

[0027] Each of these injectors 15 and 16 is connected to an engine control unit (hereinafter referred to as "ECU") 35 as "control means" so as to control the opening / closing timing and opening / closing time of the solenoid valve. .

[0028] Further, a fuel pressure sensor 36 and a fuel temperature sensor 37 disposed in the DI delivery pipe 23 are connected to the ECU 35, and an engine as an internal combustion engine speed detecting means is connected to the ECU 35. An engine speed sensor 38 for detecting the engine speed, an engine load sensor 39 for detecting the engine load as an internal combustion engine load detecting means, and a water temperature sensor 41 for detecting the temperature of the engine cooling water as a water temperature detecting means are connected. Yes. The engine operating state is detected by the engine speed sensor 38 and the engine load sensor 39, and the engine temperature state is detected by the water temperature sensor 41.

[0029] The operation state detection means for detecting the operation state of the internal combustion engine includes the internal combustion engine speed detection means, the internal combustion engine load detection means, the water temperature detection means, and the like.

[0030] As the engine load sensor 39, for example, an intake air amount detection sensor as an intake air amount detection means for detecting an intake air amount, and an accelerator opening detection sensor as an accelerator opening detection means for detecting an accelerator opening Or an intake pipe negative pressure detection sensor or the like as an intake pipe negative pressure detection means for detecting the intake pipe negative pressure.

[0031] Various actuators 40 are connected to the ECU 35, and the actuator 40 is configured to be controlled by a signal from the ECU 35. The ECU 35 acquires information from the engine speed sensor 38, the engine load sensor 39, and the water temperature sensor 41 at predetermined sampling times, and the DI injector 15 and the PFI injector 16 inject fuel into the cylinder 12, respectively. The required injection amount required to do this is obtained.

[0032] The ECU 35 controls the ignition timing for igniting the air-fuel mixture in the combustion chamber. It is configured as follows.

[0033] Specifically, the storage means (storage unit 35a) included in the ECU 35 stores an ignition timing map corresponding to the operating state of the internal combustion engine, and the central processing unit (central processing unit 35b) of the ECU 35 stores these maps. The ignition timing is controlled according to the operating state of the internal combustion engine by performing calculations based on the installed software and other values.

[0034] Further, the central processing means 35b of the ECU 35 cooperates with various programs stored in the storage unit 35a and controls the injection amount control means (injection amount) for controlling the fuel injection amount of the DI injector 15 and the PFI injector 16. Functions such as the control unit 35c), ignition timing control means for controlling the ignition timing of the cylinder 12 (ignition timing control section 35d), and ignition timing calculation means for calculating the ignition timing of the cylinder 12 (ignition timing calculation section 35e). Realize.

The ECU 35 includes four ignition timing maps and a correction amount map as ignition timing maps.

FIG. 5 shows a schematic diagram of four ignition timing maps provided in the ECU 35. The four ignition timing maps are: (1) The ignition timing of the internal combustion engine when fuel injection is performed using only the DI injector 15 (maximum spark advance for best torque, hereinafter referred to as “MBT”). The first ignition timing map assigned based on the operating state of the internal combustion engine (A), (2) When the fuel injection is performed using only the DI injector 15, the ignition timing of the internal combustion engine is determined as the knock limit torque. Second ignition timing map (Β) and (3) Ρ FI injector 16 only assigned based on the operating state of the internal combustion engine so that it almost coincides with the occurrence timing (hereinafter referred to as “TK”) The third ignition timing map (C), (4) assigned by the PFI injector 16 only, based on the operating state of the internal combustion engine so that the ignition timing of the internal combustion engine substantially matches ΜΒΤ! Ignition of the internal combustion engine Four sheets of the fourth ignition timing map (D) assigned based on the operating state of the internal combustion engine so that the timing substantially coincides with ΤΚ are provided. Each ignition timing map uses the engine speed (rpm) and engine load as parameters, and values of ignition timing are assigned at regular intervals for values up to WOT (Wide Open Throttle).

FIG. 6 shows a schematic diagram of the correction amount map. The correction amount map uses the engine coolant temperature as a parameter, and the ignition timing for A ° C, B ° C, ··· 'N ° C (A, B, ··· Ν is a predetermined value). The correction amount (correction angle value) to be corrected is assigned.

The ECU 35 functions as an ignition timing calculation means for calculating the ignition timing in the cylinder 12 using the values of the four ignition timing maps and the correction amount map, and the ignition plug 14a It has a function as ignition timing control means for issuing a command to ignite.

FIG. 7 is a schematic diagram showing the principle of ignition timing control of the ECU 35 in this embodiment. In the figure, the horizontal axis indicates the ignition timing Ig. T (the right direction is the advance side and the left direction is the retard side), and the vertical axis is the torque.

[0040] When the torque value with respect to the engine ignition timing is illustrated, a mountain-shaped curve (hereinafter referred to as "ignition timing-torque curve") is drawn, and the peak of the ignition timing-torque curve is MBT is shown, and TK comes to one side of the vertex. Ignition timing The shape of the torque curve, the apex of the curve, and the position of TK on the curve differ depending on whether the DI injector 15 is used or the PFI indicator 16 is used. Therefore, for example, the engine speed sensor 38 and the engine load sensor 39 obtain one value at one sampling time, and the values at this time are shown as points rl to r4 (all shown in FIGS. 5A to 5D). As shown in Fig. 7, rl and r2 are points on one ignition timing-torque curve (DI = 100% curve in Fig. 7), and r3 and r4 are other ignition points as shown in Fig. 7. Time Points on the torque curve (PFI = 100% curve in Fig. 7).

[0041] When driving while adjusting the fuel injection amount of the DI injector 15 and the PFI injector 16 according to the operating state of the engine, the value interpolated depending on the ratio of the fuel injection amounts of the injectors 15 and 16 As shown in Fig. 7, the interpolated ignition timing between one ignition timing torque curve (D 1 = 100% curve) and the other ignition timing-torque curve (PFI = 100% curve). A torque curve (intermediate curve) is formed. Ignition timing of the interpolated value On the torque curve, the first interpolated value r5 is formed at the intersection with the straight line connecting rl and r3, and the second interpolated value r6 at the intersection with the straight line connecting r2 and r4 Is formed.

[0042] Of the first interpolated value r5 and the second interpolated value r6, if the value positioned on the retard side is the ignition timing of the cylinder 12, the DI injector 15 and the PFI injector 16 are! Even if it is used at the ratio of the injection amount, the occurrence of knocking in the cylinder 12 can be avoided and optimal ignition timing control can be performed. Therefore, in the case shown in FIG. 7, the second interpolation value r6 is set as the ignition timing of the cylinder 12. And apply.

FIG. 8 is a flowchart showing an ignition timing control procedure of the engine according to this embodiment. Hereinafter, the operation of this embodiment will be described with reference to this flowchart.

The ECU 35 reads the values of the engine speed sensor 38, the engine load sensor 39, and the water temperature sensor 41 at every predetermined sampling time (step Sl). The ECU 35 sets the fuel injection amount ratio (fuel injection ratio) of the DI injector 15 and the PFI injector 16 based on the engine speed value and the engine load value read in step S1 (step S2). Depending on the calculation results, there are three cases: fuel injection only for DI injector 15, fuel injection only for PFI injector 16, and fuel injection for both DI injector 15 and PFI injector 16. Will occur.

[0045] The ECU 35 reads the first to fourth ignition timing maps (A) to (D) (step S3).

The ECU 35 further reads a correction amount map based on the read value of the water temperature sensor 41 (step S4).

[0047] The ECU 35 performs the following calculations (1) to (4) to calculate the ignition timing (step S5).

(1) Based on the engine speed and intake air amount values read at step SI and the four ignition timing maps read at step S3, ECU35

[0048] (a) The ratio of the fuel injection amount of the DI injector 15 based on the first ignition timing map (A) is 10

Ignition timing in MBT at 0%

(B) The ratio of the fuel injection amount of the DI injector 15 based on the second ignition timing map (B) is 10

Ignition timing at TK at 0%

[0050] (c) Ratio of fuel injection amount of PFI injector 16 based on third ignition timing map (C) is 1

Ignition timing in MBT at 00%

[0051] (d) The ratio of the fuel injection amount of the PFI injector 16 based on the fourth ignition timing map (D) is 1

Ignition timing at TK at 00%

Are calculated as basic ignition timings.

[0052] When the read engine speed value and engine load value match the values assigned in the first to fourth ignition timing maps (A) to (D), each ignition timing The values on the map are the ignition timings (a) to (d). [0053] If the read engine speed value and engine load value do not match the values assigned on the first to fourth ignition timing maps (A) to (D), each ignition timing The value is calculated based on the neighboring values on the map. For example, as shown in FIG. 5, when the point P, which is an unassigned point, is indicated in the engine speed value, the engine load value, and the power ignition timing maps (A) to (D), , Calculate the distance from the points ql to q4, which are assigned values in the vicinity of point P around 4 points, to the values of points ql to q4, the distance from point ql to point P, ... Multiply the values depending on the distance to P, respectively, and the result of multiplication will be the value of the ignition timing at point P.

(2) The value obtained by interpolating the value of (a) calculated in (1) and the value of (c) is defined as the first interpolation value Ig. T (MB T). In the interpolation calculation, the values of (a) and (c) are also calculated depending on the ratio of the fuel injection amounts of the DI injector 15 and the PFI injector 16 calculated in step S2. For example, if the ratio of the fuel injection amount is 60% for DI injector 15 and 40% for PFI injector 16, the value is calculated by the calculation such as (a) X O. 6+ (c) X O. 4.

(3) The value obtained by interpolating the values of (b) and (d) calculated in (1) is the second interpolation value Ig. T (TK). Interpolation is performed in the same manner as (2) above.

(4) Compare the first interpolation value Ig. T (MBT) with the second interpolation value Ig. T (TK), and read the value of V, deviation or retarded side in step S4. The value obtained by adjusting the correction amount is calculated as the ignition timing Ig.T.

[0054] After the procedure of step S5, the ECU 35 ignites the fuel in the cylinder 12 at the ignition timing calculated in step S5 (step S6).

[0055] The above procedure is repeated until the engine is stopped (step S7).

[0056] As described above, in this embodiment, the ECU 35 controls the ignition timing of the cylinder 12 using the first and second ignition timing maps in the DI method and the third and fourth timing maps in the PFI method. Thus, it becomes possible to make the ignition timing of the cylinder 12 correspond to MBT and TK, respectively, by simple control.

[0057] According to this embodiment, the ignition timings (a) to (d) are calculated by referring to the values assigned in the first to fourth ignition timing maps (A) to (D). In each ignition timing map (A) to (D), if there is no value assignment, each ignition timing map (A) It becomes possible to easily calculate the value based on (D).

[0058] Also, according to this embodiment, the first and fourth ignition timing maps (A) to (D) are obtained when fuel is injected using only the DI injector 15 or only the PFI injector 16. By assigning only the ignition timing, there is no need to repeat the experiment while adjusting the fuel injection amount using both injectors 15 and 16 when creating the map, and the ignition timing map (A) ~ (D) can be created.

[0059] Further, according to this embodiment, the ignition timing maps (A) and (C) of the maximum torque generation timing of the DI method and the PFI method are used to perform interpolation calculation depending on the ratio of the fuel injection amount. Similarly, using the ignition timing maps (B) and (D) of the knocking limit torque generation timing of the DI method and PFI method, the interpolation value is calculated according to the ratio of the fuel injection amount, and the second interpolation value is calculated. The interpolated value of the first and second interpolated values is calculated as the ignition timing of the cylinder, so that two fuel injection methods, the PFI method and the DI method, are combined. Even if the internal combustion engine is driven while adjusting the fuel injection amount of the DI injector 15 and the PFI indicator 16 according to the operating state of the engine, it is only necessary to use four ignition timing maps. Ignition timing without complicated calculation processing It can be maintained in a state suitable for rolling state.

[0060] According to this embodiment, the engine speed sensor 38 and the engine load sensor 39 can detect the engine speed and the load, and the ignition is performed using the engine speed and the engine load as a parameter. Time control can be realized.

[0061] According to this embodiment, at least one of the intake air amount detection sensor, the accelerator opening detection sensor, and the intake pipe negative pressure detection sensor is provided as the internal combustion engine load detection means, so that it is applied to the engine. The load amount can be detected accurately.

[0062] According to this embodiment, the coolant temperature of the engine is detected by the water temperature sensor 41, and the correction amount of the ignition timing is calculated depending on the water temperature, thereby affecting the ignition timing. The ignition timing can be adjusted based on the warm-up condition.

[0063] In the above embodiment, the correction amount is calculated based on the coolant temperature of the engine! However, the value is steadily detected reflecting the operating state of the engine. Anything that can be used. [0064] In the above-described embodiment, the number of power injectors 15 and 16 provided with DI injectors 15 and PFI injectors 16 for each cylinder 12 may not be one for each cylinder. Good. As an installation form of both the injectors 15 and 16 other than the above embodiment, for example, a DI indicator 15 is provided for each cylinder 12, and the upstream side of the intake pipe disposed in the intake port 13 of each cylinder 12 is set to 1 A configuration in which a single PFI indicator 16 is provided in the bundled intake pipe section is conceivable.

[0065] The above embodiment shows an example of the embodiment of the present invention, and does not indicate that the present invention is limited to this embodiment. ,.

Explanation of symbols

11 · · · Engine

12 · • Same

is •• DI injector

le- •• PFI injector

35 •• ECU

38 · • 'Engine speed sensor

39 · · · Engine load sensor

40 ·································

41 · · · Water temperature sensor

Claims

The scope of the claims

[1] In-cylinder injector and intake pipe injector;

An operating state detecting means for detecting the operating state of the internal combustion engine;

An injection amount control means for monitoring the operating state and controlling the fuel injection amount of each of the in-cylinder injector and the intake pipe injector depending on the operating state;

A first ignition timing map assigned based on the operating state of the internal combustion engine so that the ignition timing of the internal combustion engine when fuel injection is performed using only the in-cylinder injector is substantially the same as the maximum torque generation timing; And a second ignition timing pine assigned based on the operating state of the internal combustion engine so that the ignition timing of the internal combustion engine when fuel is injected using only the in-cylinder injector is substantially coincident with the knocking limit torque generation timing. And the third timing assigned based on the operating state of the internal combustion engine so that the ignition timing of the internal combustion engine when the fuel injection is performed using only the intake pipe injection injector substantially matches the maximum torque generation timing. The ignition timing map and the ignition timing of the internal combustion engine when fuel injection is performed using only the intake pipe injector are knocking limits. Storage means comprising a fourth ignition timing map assigned based on the operating state of the internal combustion engine so as to substantially coincide with the torque generation timing;

Ignition timing control means for controlling the ignition timing of the cylinder using the ratio of the fuel injection amount injected by the in-cylinder injector and the intake pipe injector and the four types of ignition timing maps, respectively.

A dual fuel injection internal combustion engine characterized by comprising:

[2] In the operation state detected by the operation state detection means, the basic ignition timing is calculated with reference to the values assigned in the first to fourth ignition timing maps, and depends on the ratio of the fuel injection amount Calculating a first interpolation value obtained by interpolating the basic ignition timing of the first ignition timing map and the basic ignition timing of the third point fire timing map, and depending on the ratio of the fuel injection amount A second interpolation value obtained by interpolating the basic ignition timing of the second ignition timing map and the basic ignition timing of the fourth ignition timing map is calculated, and the first interpolation value, the second interpolation value, Compare either the retarded side of the Ignition timing calculation means for setting the interpolation value as the ignition timing of the cylinder is provided.

The dual-fuel-injection internal combustion engine according to claim 1, wherein

[3] The operating state detecting means includes a water temperature detecting means for detecting the temperature of the cooling water of the internal combustion engine,

The ignition timing calculation means calculates a correction amount of the ignition timing of the cylinder depending on the coolant temperature.

The dual fuel injection internal combustion engine according to claim 2, wherein

[4] The operating state detection means includes:

An internal combustion engine speed detection means;

Internal combustion engine load detection means;

2. The dual fuel injection internal combustion engine according to claim 1, further comprising:

[5] The internal combustion engine load detection means includes:

Intake air amount detection means;

Accelerator opening detection means;

Intake pipe negative pressure detection means and

5. The dual fuel injection internal combustion engine according to claim 4, comprising at least one of the two.